Morphing (or metamorphosis) of polygonal meshes involves the creation of a smooth transition from a source mesh to a target mesh. For two meshes, there are numerous ways to transform one to the other. Algorithms for morphing are mainly evaluated by criteria related to the ease of user control and the visual quality of morphing sequence. Morphing is such an aesthetic problem that fully automatic methods cannot meet all the needs that arise in all applications. Therefore, user interaction is important and unavoidable.
A mesh morphing process basically consists of two steps: establishing the correspondence where each vertex of a source mesh is mapped to a vertex of a target mesh, and calculating the interpolation where trajectories are defined for all corresponding vertices.
Current morphing works usually concentrate on the computational issues and overlook the interactive process of specifying and modifying user requirements. To date, there is still no good scheme to make user interaction intuitive, flexible and efficient. For example, to pair a leg of a duck with a leg of a dinosaur as corresponding, users generally have to express such a requirement in terms of many low-level vertex correspondences. Such a way of specifying correspondence is usually neither intuitive nor natural, especially when two original meshes are very different in shapes.
There is therefore a need to provide a method and system for generating morphing sequences, which can facilitate a more intuitive user interaction.